Risk Management And Derivatives (Changes In Foreign Currency Exchange Rates And Derivative Foreign Currency Forward Contracts) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Foreign Currency Exchange Gain Loss [Line Items]
Maturity of foreign currency forward contract			14 months
Unrealized foreign currency exchange rate gains (losses)	$ (5,454)	$ (4,981)	$ (24,677)	$ (4,881)
Realized foreign currency exchange rate gains (losses)	(1,858)	81	6,999	303
Unrealized derivative gains (losses)	(112)	(134)	(182)	(152)
Realized derivative gains (losses)	(3,559)	(1,679)	(12,196)	(748)
Fair Value, Inputs, Level 2 [Member]
Foreign Currency Exchange Gain Loss [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	$ 1,371	$ 8	$ 1,371	$ 8	$ 806